A known type of latch arrangement for securing an implement to a carrier mounted to lifting arms of a boom comprises a rod arrangement mounted to the carrier for being shifted laterally between latched and unlatched positions, with the rod arrangement being spring biased to its latched position. The rod arrangement can be either manually or hydraulically moved to the unlatched position, where a secondary latch is engaged by partially rotating the rod by the action of a second spring. The rod arrangement can then be released with the rod arrangement remaining in an arrested unlatched position until an implement coupled to the carrier is rolled back so as to engage the latch rod arrangement causing it to rotate out of its arrested position thereby disengaging the secondary latch permitting the latch rod arrangement to be moved to its latched position by the biasing spring. Such a prior art securing arrangement is disclosed in U.S. Pat. No. 7,001,137.
Another known type of latch arrangement includes a remotely operable latch rod arrangement which is biased toward a latched position and is selectively moveable to an unlocked position by an extensible and retractable hydraulic cylinder controlled by a solenoid operated valve which is controlled by a circuit including a latching control switch and a height control switch connected in series so that both must be closed to complete a circuit to the control valve so as to prevent unlatching if the height sensing switch senses a height above a preselected safe height for implement detachment. U.S. Pat. No. 7,467,918 discloses such a prior art latch rod control.
One drawback associated with the patented designs is that a failure of the biasing mechanism when the implement is attached to the boom could result in the latch rod migrating to its unlatched position. Another drawback of the patented designs is that an operator may not be aware if the latching rod arrangement becomes jammed or the like resulting in a partially latched implement. Further, while hydraulic cylinders are effective devices for moving the latching rod arrangements to their unlatched positions, hydraulic fluid leakage is always a problem and the provision of hydraulic hoses and control valves often take up valuable space and require special design considerations resulting in increased cost.